One-Dimensional Thiocyanato-Bridged Fe(II) Spin Crossover Cooperative Polymer With Unusual FeN5S Coordination Sphere.

We present here a novel example of spin crossover phenomenon on a Fe(II) one-dimensional chain with unusual N5S coordination sphere. The [{Fe(tpc-OMe)(NCS)(µ-NCS)} n] (1) compound was prepared using the tridentate tpc-OMe ligand (tpc-OMe = tris(2-pyridyl)methoxymethane), FeCl2·4H2O, and the KSCN salt. Crystallographic investigations revealed that the Fe(II) ions are connected by a single bridging NCS- ligand (µ-κN:κS-SCN coordination mode) to afford a zigzag neutral chain running along the [010] direction, in which the thiocyanato bridging groups adopt a cis head-to-tail configuration. The (N5S) metal environment arises from one thiocyanato-κS and two thiocyanato-κN ligands and from three pyridine of the fac-tpc-OMe tripodal ligand. This compound presents a unique extension of Fe(II) binuclear complexes into linear chains built on similar tripodal ligands and bridging thiocyanate anions. Compound 1 shows a spin crossover (SCO) behavior which has been evidenced by magnetic, calorimetric, and structural investigations, revealing a sharp cooperative spin transition with a transition temperature of ca. 199 K. Temperature scan rate studies revealed a very narrow hysteresis loop (∼1 K wide). Photoswitching of this compound was also performed, evidencing a very fast relaxation process at low temperature. Among other factors, the linearity of the N-bound terminal thiocyanato ligand appears as the main structural characteristic at the origin of the presence of the SCO transition in compound 1 and in the two others Fe(II) previous systems involving thiocyanato-bridges and tripodal tris(2-pyridyl)methane ligands.

Spin crossover iron(II) coordination polymer chains: syntheses, structures, and magnetic characterizations of [Fe(aqin)2(µ2-M(CN)4)] (M = Ni(II), Pt(II), aqin = quinolin-8-amine).

New Fe(II) coordination polymeric neutral chains of formula [Fe(aqin)2(µ2-M(CN)4)] (M = Ni(II) (1) and Pt(II) (2)) (aqin = Quinolin-8-amine) have been synthesized and characterized by infrared spectroscopy, X-ray diffraction, and magnetic measurements. The crystal structure determinations of 1-2 reveal in both cases a one-dimensional structure in which the planar [M(CN)4](2-) (M = Ni(II) (1) and Pt(II) (2)) anion acts as a µ2-bridging ligand, and the two aqin molecules as chelating coligands. Examination of the intermolecular contacts in the two compounds reveals that the main contacts are ascribed to hydrogen bonding interactions involving the amine groups of the aqin chelating ligands and the nitrogen atoms of the two non bridging CN groups of the [M(CN)4](2-) (M = Ni(II) (1) and Pt(II) (2)) anion. The average values of the six Fe-N distances observed respectively at room temperature (293 K) and low temperature (120 K), that is, 2.142(3) and 2.035(2) Å for 1, and 2.178(3) and 1.990(2) Å for 2, and the thermal variation of the cell parameters (performed on 2) are indicative of the presence of an abrupt HS-LS spin crossover (SCO) transition in both compounds. The thermal dependence of the product of the molar magnetic susceptibility times the temperature (χmT), in cooling and warming modes, confirms the SCO behavior at about 145 and 133 K in 1 and 2, respectively, and reveals the presence of a small thermal hysteresis of about 2 K for each compound.

Measurement of translesion synthesis by fluorescent capillary electrophoresis: 7,8-dihydro-8-oxodeoxyguanosine bypass modulation by natural products.

Translesion synthesis (TLS) relies on a series of specialized DNA polymerases able to insert a base either correctly or incorrectly opposite a lesion on a DNA template strand during replication or post-repair synthesis. To measure the correct or mutagenic outcome of 7,8-dihydro-8-oxodeoxyguanosine (8-oxodG) bypass by TLS DNA polymerases, a capillary electrophoresis (CE) method with fluorescent label has been developed. Two oligonucleotides were designed and hybridized: (i) a 72-mer oligonucleotide framing one 8-oxodG at position 40 and (ii) the 39-mer oligonucleotide complementary to the first strand from the 3' end to the lesion and labeled at the 5' end with a fluorochrome. After incubation with FHs 74 Int human intestinal epithelial cell nuclear proteins, in the presence of either deoxyadenosine triphosphate (dATP) or deoxycytidine triphosphate (dCTP), and denaturation, the resulting elongated oligomers were analyzed by fluorescent capillary electrophoresis. This primer extension assay was then validated in terms of linearity (linear range=0.5-2.5 nM), detectability (limits of detection and quantification=0.023 and 0.091 nM, respectively), and precision (total precisions=8.1% and 3.7% for dATP and dCTP, respectively, n=9). The addition of some natural phytochemicals to the reaction mix significantly influences the outcome of TLS either in an error-free way or in a mutagenic way.

Trends in Pediatric Emergency and Inpatient Healthcare Use for Mental and Behavioral Health Among North Carolinians During the Early COVID-19 Pandemic.

BACKGROUND: Widespread school closures and health care avoidance during the COVID-19 pandemic led to disruptions in access to pediatric mental health care. METHODS: We conducted a retrospective study of emergency and inpatient administrative claims from privately insured children aged 6-20 years in North Carolina between January 2019 and December 2020. We compared rates of emergency department (ED) visits (per 100 000 person-days) and risks of hospitalizations (per 100 000 persons) with diagnosis codes in each category (mental/behavioral health; suicidal ideation, suicide attempt, and intentional self-harm [SI/SA/ISH]; and social issues) across 3 time periods (pre-pandemic, lockdown, and reopening). We calculated the proportion and 95% confidence intervals (CI) of total ED visits and total hospitalizations attributable to mental/behavioral health and SI/SA/ISH across the 3 time periods. RESULTS: Rates of all categories of ED visits decreased from pre-pandemic to the lockdown period; from pre-pandemic to the reopening period, mental/behavioral health visits decreased but rates of SI/SA/ISH visits were unchanged. The proportion of ED visits attributable to mental/behavioral health increased from 3.5% (95% CI 3.2%-3.7%) pre-pandemic to 4.0% (95% CI 3.7%-4.3%) during reopening, and the proportion of SI/SA/ISH diagnoses increased from 1.6% (95% CI 1.4%-1.8%) pre-pandemic to 2.4% (95% CI 2.1%-2.7%) during the reopening period. Emergency care use for social issues and hospital admissions for mental/behavioral health and SI/SA/ISH diagnoses were unchanged across the study periods. CONCLUSIONS: In the early pandemic, pediatric mental health care and acute suicidal crises accounted for increased proportions of emergency care. During pandemic recovery, understanding the populations most impacted and increasing access to preventative mental health care is critical.

On-chip microelectrophoresis for the study of in vitro nonhomologous end-joining DNA double-strand break repair.

Oligomerization of linearized plasmids by nuclear proteins extracts, a recognized measure of nonhomologous end-joining (NHEJ) repair capacity, is typically assessed through agarose gel electrophoresis, a labor-intensive procedure. In the current study, a more convenient NHEJ assay was developed using microchips that allow scaled-down separation and quantification. This microchip method allows a considerable reduction in sample amount and analysis time with similar costs and comparable or slightly better precision. Data obtained with quercetin and wortmannin show that the method can be applied to the screening of food components and natural products for positive and negative modulators of NHEJ, potential chemopreventive and indirect genotoxic compounds, respectively.

An overview of cancer chemopreventive potential and safety of proanthocyanidins.

Cancer is a major public health problem worldwide. Over two-thirds of cancer-related deaths could most probably be prevented through lifestyle modification, particularly through dietary means. Proanthocyanidins (PAs), the most abundant polyphenolic substances after lignin in the plant kingdom, have been widely investigated for their chemopreventive potential. The PAs literature has, however, been mostly concerned with positive cardiovascular activities, and recent reviews about cancer chemoprevention are scarce. The present review highlights a series of in vitro and in vivo studies indicating ( 1 ) that PAs can act as anticarcinogenic agents through their antioxidant, apoptosis-inducing, immuno-modulating, and/or enzyme modulating properties, effects on epigenetics; and ( 2 ) that PAs could be particularly safe dietary compounds. These convergent data encourage further research to better understand the many aspects of cancer chemoprevention by PAs.

A biocodicological analysis of the medieval library and archive from Orval Abbey, Belgium.

Biocodicological analysis of parchments from manuscript books and archives offers unprecedented insight into the materiality of medieval literacy. Using ZooMS for animal species identification, we explored almost the entire library and all the preserved single leaf charters of a single medieval Cistercian monastery (Orval Abbey, Belgium). Systematic non-invasive sampling of parchment collagen was performed on every charter and on the first bifolium from every quire of the 118 codicological units composing the books (1490 samples in total). Within the genuine production of the Orval scriptorium (26 units), a balanced use of calfskin (47.1%) and sheepskin (48.5%) was observed, whereas calfskin was less frequent (24.3%) in externally produced units acquired by the monastery (92 units). Calfskin was preferably used for higher quality manuscripts while sheepskin tends to be the standard choice for 'ordinary' manuscript book production. This finding is consistent with thirteenth-century parchment accounts from Beaulieu Abbey (England) where calfskin supply was more limited and its price higher. Our study reveals that the making of archival documents does not follow the same pattern as the production of library books. Although the five earliest preserved charters are made of calfskin, from the 1230s onwards, all charters from Orval are written on sheepskin.

Animal species identification in parchments by light.

Recently, historical and conservation studies have attached an increasing importance to investigating the materials used in historic documents. In particular, the identification of the animal species from which parchments are made is of high importance and is currently performed by either genetic or proteomic methods. Here, we introduce an innovative, non-invasive optical method for identifying animal species based on light-parchment interaction. The method relies on conservation of light energy through reflection, transmission and absorption from the sample, as well as on statistical processing of the collected optical data. Measurements are performed from ultraviolet (UV) to near-infrared (NIR) spectral ranges by a standard spectrophotometer and data are processed by Principal Component Analysis (PCA). PCA data from modern parchments, made of sheep, calf and goat skins, are used as a database for PCA analysis of historical parchments. Using only the first two principal components (PCs), the method confirmed visual diagnostics about parchment appearance and aging, and was able to recognise the origin species of historical parchment of among database clusters. Furthermore, taking into account the whole set of PCs, species identification was achieved, with all results matching perfectly their proteomic counterparts used for method assessment. The validated method compares favourably with genetic and proteomic methods used for the same purpose. In addition to animals' proteomic and genetic signatures, a unique "optical fingerprint" of the parchments' origin species is revealed here. This new method is non-invasive, straightforward to implement, potentially cheap and accessible to scholars and conservators, with minimal training. In the context of cultural heritage, the method could help solving questions related to parchment production and, more generally, medieval writing production.

An interdisciplinary study around the reliquary of the late cardinal Jacques de Vitry.

The reliquary of Jacques de Vitry, a prominent clergyman and theologian in the early 13th century, has experienced several transfers over the last centuries, which seriously question the attribution of the remains to the late Cardinal. Uncertainty about the year of his birth poses an additional question regarding his age at death in 1240. The reliquary, located in the Saint Marie d'Oigines church, Belgium, was reopened in 2015 for an interdisciplinary study around his relics as well as the Treasure of Oignies, a remarkable cultural heritage notably built from Jacques de Vitry's donation. Anthropological, isotopic and genetic analyses were performed independently on the remains found in the reliquary. Results of the analyses provided evidence that the likelihood that these remains are those of Jacques de Vitry is very high: the remains belong to the same human male individual and the historical tradition about his age is confirmed. In addition, a separate relic (left tibia) was analysed and found to match with the remains of the reliquary (right tibia). The unique Jacques de Vitry's mitre, made of parchment, was sampled non-destructively and the extracted parchment collagen was analysed by a proteomic method in order to determine the animal species. The results showed that, surprisingly, not all parts of the mitre were made from the same species. All together, these findings are expected to fertilize knowledge carried by historical tradition around the relics of Jacques de Vitry and his related cultural heritage.

An unprecedented trinuclear FeII triazole-based complex exhibiting a concerted and complete sharp spin transition above room temperature.

We report a triazole-based trinuclear complex as the first example that displays a complete one-step first-order [HS-HS-HS] ↔ [LS-LS-LS] spin transition at 318 K. The strong ferro-elastic interactions, between the three metal centers, have been identified as the source of the concerted spin transition in this trinuclear complex.

Humanization of an anti-ICAM-1 antibody with over 50-fold affinity and functional improvement.

The monoclonal antibody 1A6 binds to human intercellular adhesion molecule 1 (ICAM-1, CD54) and inhibits infection by 90% of human rhinovirus (HRV) serotypes. To make a therapeutic molecule for preventing and treating HRV infection, we humanized a single chain antibody (scFv), 1A6, by a structure-guided complementarity-determining region (CDR) grafting procedure. Our final humanized 1A6 scFv does not retain any mouse back mutations in the framework. Without changing the CDR sequences, the humanized 1A6 scFv demonstrates over 50-fold improvement in both affinity for ICAM-1 and protection efficacy against HRV infection in vitro.

Recent advances in rhinovirus therapeutics.

Human rhinoviruses are the major causative agents of the common cold. Because there are greater than 100 viral serotypes, little immunological protection is afforded to humans by prior rhinovirus exposure, which accounts for the high incidence of infection. In most cases, rhinovirus leads to a short self-limiting illness. However, for asthmatics, the elderly and immunocompromised patients, rhinovirus infection can lead to life-threatening complications. This has spurred a consistent effort over recent decades to identify effective treatments and preventions for rhinovirus infection. While some work has focused on alleviating the symptoms induced as a result of inflammatory pathways stimulated by rhinoviruses, the majority of the research has been focused on limiting or preventing viral infection altogether. Various approaches have been taken to halt rhinovirus infection. Prevention of virus-cell interaction has been the aim of research on viral capsid binders and cell receptor blockers. Interference with correct viral protein processing is the goal of the design and testing of protease inhibitors. Current work is attempting to interfere with viral RNA replication by testing silencing RNA molecules. In this review, we will discuss recent advances in the development and testing of human rhinovirus therapeutics.

Effects of chemopreventive natural products on non-homologous end-joining DNA double-strand break repair.

Double-strand breaks (DSBs) may result from endogenous (e.g., reactive oxygen species, variable (diversity) joining, meiotic exchanges, collapsed replication forks, nucleases) or exogenous (e.g., ionizing radiation, chemotherapeutic agents, radiomimetic compounds) events. DSBs disrupt the integrity of DNA and failed or improper DSBs repair may lead to genomic instability and, eventually, mutations, cancer, or cell death. Non-homologous end-joining (NHEJ) is the major pathway used by higher eukaryotic cells to repair these lesions. Given the complexity of NHEJ and the number of proteins and cofactors involved, secondary metabolites from medicinal or food plants might interfere with the process, activating or inhibiting repair. Twelve natural products, arbutin, curcumin, indole-3-carbinol, and nine flavonoids (apigenin, baicalein, chalcone, epicatechin, genistein, myricetin, naringenin, quercetin, sakuranetin) were chosen for their postulated roles in cancer chemoprevention and/or treatment. The effects of these compounds on NHEJ were investigated with an in vitro protocol based on plasmid substrates. Plasmids were linearized by a restriction enzyme, generating cohesive ends, or by a combination of enzymes, generating incompatible ends; plasmids were then incubated with a nuclear extract prepared from normal human small-intestinal cells (FHS 74 Int), either treated with these natural products or untreated (controls). The NHEJ repair complex from nuclear extracts ligates linearized plasmids, resulting in plasmid oligomers that can be separated and quantified by on-chip microelectrophoresis. Some compounds (chalcone, epicatechin, myricetin, sakuranetin and arbutin) clearly activated NHEJ, whereas others (apigenin, baicalein and curcumin) significantly reduced the repair rate of both types of plasmid substrates. Although this in vitro protocol is only partly representative of the in vivo situation, the natural products appear to interfere with NHEJ repair and warrant further investigation.

Measurement of the influence of flavonoids on DNA repair kinetics using the comet assay.

The complexity of DNA repair mechanisms infers that xenobiotics, derived from food and medicinal plants, may interfere in the process, activating or inhibiting repair. Different flavonoids were investigated, at the highest non-toxic concentration, for their capacity to modulate DNA repair 12, 24 and 48 h after a non-reactive oxygen species (ROS) treatment involving ethylmethanesulfonate (2mM; 2h). After 12h, DNA fragmentation is substantially increased by quercetin; this effect disappears at subsequent sampling times. At 24h, fragmentation is reduced in the presence of apigenin and slightly increased by sakuranetin. None of the flavonoids tested inhibited repair, which seems complete at 48 h. Ex vivo comet experiments were then performed to assess the excision capabilities of protein extracts obtained from flavonoid-treated cells. Quercetin increases non-specific endonuclease activity, apigenin and epicatechin increase the excision of damages and sakuranetin increases both non-specific and specific enzymatic activities. Combining direct repair and ex vivo experiments yields complementary data that may lead to characterizing mechanisms.

Abortive autophagy induces endoplasmic reticulum stress and cell death in cancer cells.

Autophagic cell death or abortive autophagy has been proposed to eliminate damaged as well as cancer cells, but there remains a critical gap in our knowledge in how this process is regulated. The goal of this study was to identify modulators of the autophagic cell death pathway and elucidate their effects on cellular signaling and function. The result of our siRNA library screenings show that an intact coatomer complex I (COPI) is obligatory for productive autophagy. Depletion of COPI complex members decreased cell survival and impaired productive autophagy which preceded endoplasmic reticulum stress. Further, abortive autophagy provoked by COPI depletion significantly altered growth factor signaling in multiple cancer cell lines. Finally, we show that COPI complex members are overexpressed in an array of cancer cell lines and several types of cancer tissues as compared to normal cell lines or tissues. In cancer tissues, overexpression of COPI members is associated with poor prognosis. Our results demonstrate that the coatomer complex is essential for productive autophagy and cellular survival, and thus inhibition of COPI members may promote cell death of cancer cells when apoptosis is compromised.

Dual inhibition of tumor energy pathway by 2-deoxyglucose and metformin is effective against a broad spectrum of preclinical cancer models.

Tumor cell proliferation requires both growth signals and sufficient cellular bioenergetics. The AMP-activated protein kinase (AMPK) pathway seems dominant over the oncogenic signaling pathway suppressing cell proliferation. This study investigated the preclinical efficacy of targeting the tumor bioenergetic pathway using a glycolysis inhibitor 2-deoxyglucose (2DG) and AMPK agonists, AICAR and metformin. We evaluated the in vitro antitumor activity of 2DG, metformin or AICAR alone, and 2DG in combination either with metformin or AICAR. We examined in vivo efficacy using xenograft mouse models. 2DG alone was not sufficient to promote tumor cell death, reflecting the limited efficacy showed in clinical trials. A combined use of 2DG and AICAR also failed to induce cell death. However, 2DG and metformin led to significant cell death associated with decrease in cellular ATP, prolonged activation of AMPK, and sustained autophagy. Gene expression analysis and functional assays revealed that the selective AMPK agonist AICAR augments mitochondrial energy transduction (OXPHOS) whereas metformin compromises OXPHOS. Importantly, forced energy restoration with methyl pyruvate reversed the cell death induced by 2DG and metformin, suggesting a critical role of energetic deprivation in the underlying mechanism of cell death. The combination of 2DG and metformin inhibited tumor growth in mouse xenograft models. Deprivation of tumor bioenergetics by dual inhibition of energy pathways might be an effective novel therapeutic approach for a broad spectrum of human tumors.

Prevention of human rhinovirus infection by multivalent fab molecules directed against ICAM-1.

We have developed a technology for improving avidity by making bivalent, trivalent, or tetravalent recombinant polypeptides. We designed tripartite proteins consisting of the Fab fragment of an antibody fused with a hinge derived from human immunoglobulin D that was further linked to polymerization domains derived from human coiled-coil proteins. We report here on the application of this method with a Fab domain directed against the major human rhinovirus receptor, intercellular adhesion molecule 1 (ICAM-1). Multivalent anti-ICAM-1 molecules were produced in bacteria and purified as soluble preassembled homogeneous proteins at high yield. These proteins successfully blocked rhinovirus infection in vitro, with the efficiency increasing from monomer to dimer, trimer, and tetramer. The diminished dissociation rate of these multivalent antibodies and their improved efficacy in preventing rhinovirus infection provide a foundation for producing prophylactic and therapeutic molecules against human rhinovirus, the causative agent of the majority of common colds.